1. Field of the Invention
The present invention relates to a system of making a hard copy of a digital document, and more specifically to, for example, a system for control of hard copy to prevent the hard copy of a displayed screen when a Web page transmitted from a WWW (world wide Web) server is displayed on a personal computer using a browser on the Internet, or to display a warning message and make a hard copy when a hard copy is permitted.
2. Description of the Related Art
When a hard copy of document information and image information being displayed on the display screen is to be made, the information can be printed with a special message such as `confidential`, `important`, `no copying allowed`, etc. attached to each page or a cover page, depending on the importance or the confidentiality level of the information.
The technology of automatically adding the above described special messages in special color, for example, red, to the document information when the information is printed, for example, the technology of printing document data stored on a floppy disk with a special message, etc. added in specified color based on the contents preliminarily entered for the document data when the document data is read, and the technology of outputting on the index sheet the complete index information in a comprehensible and confidential format including the index information such as confidential document, an important document, etc. are disclosed in the following documents.
Tokukaisho 63-256448 by Yasuhisa Ishizawa
Document Processing Apparatus PA1 System Application Apparatus PA1 Image Generation and Storage Apparatus
Tokukaihei 9-86015 by Masahiro Ito
Tokukaihei 6-348808 by Tatsuro Yoshioka, et al.
According to an embodiment of the present invention described later, a copy control system is applied when a hard copy of a screen displayed on the display screen is to be made by a browser for browsing sources through the Internet. Therefore, the related conventional technology is described below.
When the Internet is used, an image on a Web page transmitted from a WWW sever through a network is displayed on the display screen using a browser such as Netscape Navigator from the Netscape Corporation, etc. The user normally makes a hard copy of a digital document such as a document, image data, photographs, etc. displayed on the display screen as necessary using a printer connected to, for example, a personal computer.
FIG. 1 shows a conventional technology of copying a Web page described in a hypertext description language, for example, HTML (HyperText Markup Language). In FIG. 1, the Web page transmitted from a WWW server to a client side through a LAN, etc. is received through a line control function in an operating system such as Windows 95 from the Microsoft Corporation, etc., and is interpreted by the browsing software. The line control function receives a Web page from the server side using a user identifier, a user ID, a password, etc. as necessary. The Web page image displayed on the display device by the browser is printed as a hard copy at a request from a user.
Normally, the contents of the Web page, etc. displayed on the display device by a commonly marketed browser are widely circulated. In most cases, there are no problems as to whether or not the user should print the contents. However, if information is confidential or very important, then security control is performed by the access control unit on the WWW server side so that only a specific user assigned a user identifier or a password is allowed to access a URL (Uniform Resources Locator).
As described above, the access to confidential and important information has been limited to a specific user according to the conventional technology, but the specific user can easily make a hard copy of the information displayed by the browser. As a result, for example, the user can have the contents of the hard copy checked by a third party, thereby causing the problem that the confidential information can be revealed to others.